This invention relates to the manufacture of textiles, and more particularly to the carding of fibers, including an improved method of carding wool and fine-fiber hairs, and apparatus for carrying out the method.
In the manufacture of textiles, an implement or machine called a card or carder is utilized to process fiber stock such as grease wool or picked fleece, to disentangle, arrange and collect together the individual fibers in an arrangement suitable for spinning. The carding process, historically a handicraft, was mechanized in the mid to late eighteenth century.
A card employs "card cloth" or wire "clothing" which comprises a matrix of wire tines or teeth, set closely spaced apart in rows, in a suitable foundation such as leather, rubber or synthetic material. The wire tines are usually bent to a uniform angle, all pitched in the same general direction, the points providing in concert a surface for the action of carding fiber stock such as wool. In the carding process, two opposed wired surfaces are moved relatively in opposite directions, the wired surfaces of the adjacent cards being close to each other, but not touching or meshing. The surfaces are disposed such that the points of the wire clothing of the respective surfaces pitch in opposite directions, working point against point, and this opposition provides, in part, the tension applied to fibers disposed between the card surfaces.
Carding subjects fiber stock, a tight mass of tangled, matted fibers having nonuniform and erratic distribution throughout the mass, to forces set up between two card-cloth surfaces. Fiber stock is applied to a first one of the surfaces, where it is held, entangled among the wires. Carding takes place when there is forcible transfer of individual fibers from the first card-cloth surface to the other surface. Fibers of the stock are held by friction on the card-cloth wires of the first card. Wires of the empty card, passing near the wires of the card charged with fibers, snag and hold individual fibers of the mass, causing tension in the fibers, and it is the tension built up in the fibers in overcoming the frictional forces holding the fibers which effectuates carding. When the tension is sufficient to overcome the frictional force holding a fiber to the wire(s) of the first surface, the fiber is released, forcibly extracted and transferred to the surface of the second card with a whipping action induced by spring temper of the wires. The transferred fibers are thus collected and laid down in a coalescent web or sheet of intermeshed fibers termed a bart or sliver. The purpose of carding is to achieve a uniform distribution of density of fibers in a bart necessary to allow maximum control by the hand spinner in drafting, or by machines in drawing and spinning yarn. Depending on the type of fiber carded and the kind of yarn desired, one carding may suffice, while other fibers and blends of fibers may require additional cardings to achieve the degree of evenness and uniformity of distribution of the fibers desired for spinning. The carding process can be repeated by stripping the bart of partially carded fibers from the second surface, reapplying the batt to the first surface and carding the fibers again to further open, straighten and redistribute the fibers. Whether performed manually as a handicraft, or effected on a large scale by industrial machinery, the carding process is essentially the same.
Artisans who spin yarn by hand often prepare fiber stock for spinning by utilizing hand-held cards, which look like flat, rectangular paddles with handles; the paddles have card cloth affixed to one side. Other artisans and hand spinners prepare fibers for spinning on small, two-cylinder carding machines, called "drum carders," which have card-cloth wires disposed on the surfaces of two cylinders or drums of different size, rotating with their surfaces tangentially adjacent and parallel to each other. Large industrial carding machines employ multiple stages of carders, each stage having small worker and stripper drums set successively closer to a large main cylinder or swift, thus subjecting the fiber stock to repeated carding, and a thorough opening, cleaning and straightening of the fiber. The carded fibers are removed from the main cylinder by a dolling cylinder, as described below.
Small, drum carders utilized by artisans employ two rotating cylinders journaled on a wooden frame: a small diameter input drum or "licker-in," and a larger diameter carding drum or swift, the swift rotating considerably faster than the licker-in. Although some of these machines are powered by small electric motors, the process is essentially a handicraft, the machines being fed and stripped by hand, and commonly operated manually by a hand crank. Fiber stock loaded onto a feed pan adjacent the licker-in is impaled by the wire teeth of the smaller cylinder, pulled in and held on the surface of the cylinder as it rotates. The carding takes place along a narrow gap between the surfaces of the licker-in and the swift, called the transfer region, where the surfaces approach closely but do not touch or intermesh. Some of the fibers projecting above the teeth of the licker-in are readily caught by the wire clothing on the surface of the swift, which is moving rapidly in the opposite direction relative to the licker-in, the wires working point against point, pulling the fibers away against resistance from the smaller cylinder, thus disentangling, straightening and opening the mat of fibers, the extracted fibers cohering in the wires of the swift. After a web or batt of carded fiber of sufficient thickness is collected on the swift, the machine is stopped and the web manually stripped or doffed, and further processed by additional carding, or by spinning.
The carding process is inherently complex for the artisan because of the wide range of properties of fibers and various blends of fibers, and handicraft carding can be extremely demanding of the time and patience of the practitioner, often requiring that the fibers be passed through the drum carder several times, using different settings of drum separation, various densities of card-cloth wires, and/or different relative speeds of the drum surfaces. The spacing and parallelism of the cylinders, the pitch and density of the teeth, the relative speed of the drum surfaces, the manner and rate at which the fiber stock is input into the feed tray, and the properties (and mixes) of the fibers, are all critical factors which affect the efficacy of the carding process. Considerable experience and skill are required of the artisan to successfully card fiber with a drum carder.
The carding of fine-fiber hair such as alpaca, angora rabbit, cashmere, mohair, etc., is more difficult than processing ordinary coarse wool, because such fine fibers generally are shorter and smoother, having fewer convolutions and epidermal scales than most wool, and therefore less disposed to be held by friction on the card-cloth wires and grasped by the moving card-cloth wires of the opposed surface. Consequently, when the shorter, smoother fibers are caught by the moving wire clothing of the carding drum, many of the fibers are pulled up but not extracted from the fiber stock disposed on the input drum, while other fibers are easily released from the wire clothing of the input drum; therefore, little tension is developed in the fibers, resulting in ineffectual carding. Fibers are left protruding above the surface of both the carding and input drums, where they interfere with the carding process and build up rapidly above the wire tines to form a villous or fluffy nap. The buildup of napped fibers is believed to be caused, also, in part, by static electricity, wherein static charges induced in the smoother fibers by the motion of the drums causes the loosened fibers to extend outward from the surface of the drum. The napped fibers clog the carder, resulting in an excessively fluffy bart of partially and incompletely carded fibers. The problem of excessive fluffing is seen also in the carding of shorter, fine-fiber wools such as those produced, for example, by merino and rambouillet breeds of sheep, The problem is conventionally solved by one or more of the following: providing a more dense card clothing for processing the smooth, short fibers; adjusting the gap between the drums of the carder; or additional passes of the fluffy batts through the carding machine. However, these conventional solutions are expensive, labor intensive, time consuming, and not always effective.
Brushes are known in certain industrial carding machines; however, such brushes are not employed intrinsically in the carding process, but perform some other function apart from carding, as to extract material from rotating cylinders, or to clean waste material from particular elements of the machine. For example, in the latter instance, a rotating drum having bristles disposed in a spiral configuration cleans residual lint from the flats of cotton carders. In the former instance, a "fancy roller," utilizing long, brush-like wire clothing, working back against back in relation to the card-cloth wires of the swift, brushes up or lifts a web of carded fibers above the surface of the swift, so that the web is in a position favorable for transfer to a dolling cylinder, the element which removes the carded web from the swift.
It is therefore a principle object of my invention to provide an improved carding machine.
Another object of the invention is to provide an improved process for carding wool and fine fibers, and to provide apparatus for carrying out the process.
It is another object of my invention to provide an improved drum carder for artisans who prepare fiber for spinning.
Another object of the invention is to provide apparatus in a carding machine which inhibits the buildup of fluffy nap in a web of carded fibers.
Another object of the invention is to provide apparatus in a cylinder carding machine which prevents clogging of the transfer region of the carding mechanism with napped fibers.
Another object of the invention is to provide apparatus in a carding machine which inhibits the buildup of napped fibers on the input cylinder of the machine.
Yet another object of the invention is to provide apparatus in a cylinder carding machine which facilitates carding a wide range of stock fibers and fiber blends of different staple length, smoothness and cohesiveness, without changing the configuration of the carding machine cylinders and the card-cloth wires.
Still another object of my invention is to provide an improved cylinder carding machine having means for forcing napped fibers on the carding cylinder into the card-cloth wires of the carding machine.
Another object of the invention is to provide an improved cylinder carding machine having a brush with bristles engageable with the card clothing of the carding cylinder to brush napped fibers into the card-cloth wires positioned on an outer portion of the cylinder.